Charge forming device



March 1,1932. c. v. .MoRToN 1,847,724

CHARGE FORMING DEVICE Filed Jan. 2l! 1930 /4 /2 o lz] Mz /zo Q7 2 A A/JZ L2 "zo /Ize /za i7 3 JWM fr@ IZ M1727!! Patented Mar. 1, 1932 UNITEDSTATESPATENT OFFICE CRAIG V. MORTON, OF DAYTON, OHIO, ASSIGNOR TO DELCOPRODUCTS CORPORATION, i

DAYTON, OHIO, A CORPORATION OF DELAWARE l CHABGE FORMING DEVICEApplication filed January 21, 1930.- SeriaLNo. 422,426.'

buretors, yeach of which delivers a ,primary mixture of air and fuel toone of a plurality of secondary mixing chamberslocated adjacent theengineintake ports and in which the primary mixture is mixed withadditional air under certain operating conditi-ons.

Y livered to the cylinders from a point A. device of this character isYshown in the copending application of Fred E. Aseltine, Carl H. Kindland Wilford H. Teeter, Serial No. 288,683,flled June 27, 1928.'

It has been found desirable in devices of the character disclosed in the`above mentioned application, to celerating the flow through thesecondary mixing chamber past the end of the primary mixture deliveryconduit to effect the necessary velocity of flow through the primarymixture passages and through the secondary mixing chambers in order toenable the engine to accelerate better and to prevent fuel precipitatingout of the mixture and collecting on the walls of the secondary mixing.chamber. If such precipitation of fuel takes place, it is diflicult tosecure equaldistribution of the fuel charge to various cylinders andsuch precipitation is found particularly objectionable in the case of anL-head engine. In such type of engine where the fuel char e is deliveredfrombelow the valve instea 'of l from above the valve, there is a muchgreater tendency for the fuel to puddle inthe secondary mixing chamberthan in the overhead valve type of engine, where the fuel is deabove thevalve. In earlier devices of this same type, means have been provided toprevent the puddling of fuel in the manner describe and to effect thedesired velocity of flow through the primary mixture conduits, but suchmeans have restricted the outletbranches of the manifold to such anextent as to reduce the engine power.

It is the principal object of this invention to provide means which willincrease the velocity of iiow through the secondary mixing chambersunder all operating conditions suffi- 'the overhead valve type.

provide means for acciently to prevent puddling in, and which is soconstructed that the areaof the passage through said 'secondary mixingof the fuel therechambers willnot be sufficiently restricted to .L

materially reduce the engine power'. While this invention is'inoreparticularly adapted to anvL-head engine than to any other type, [it

will be obvious that its use is not limited to an L-head engine, butwillto a lesser degree.

effect 'the same desired result in. an engine of With this object inview, the invention consists in the provision of a Venturi tube ineachnoutlet branch of themanifoldwhich is automatically movable onvariations of ther ,engine speed so that the positon of said Venturitube relative to the primary mixture conduit will be varied and therestriction of the area at the delivery end of said conduit will beincreased as the F.

engine speed increases and the quantity of air flowing through thesecondary mixing chamber increases.

Further objects and advantages of the present invention will be apparentfrom the fol- M lowing description, refereiice being hadto theaccompanying 'drawings wherein appreferred embodiment of one form of thepresent invention is clearly shown.

In the drawings f Fig. 1 is a longitudinal section through a"` chargeforming device constructed accordance with the present invention. f v lFig. 2 is a section onthe line 2 2 ofFigr 1.

Fig. 3 is a fragmentary section through a, ,Y

branchV of the manifold showing amodified form of the presentinvention..

ThedeviceV disclosed comprises a main air manifold 10, having threeoutlet' branches, the

middle branch 12 being shown herein.v Each...

outlet branch communicates with one of the d ports of a multicylinderengine and each is provided with an attaching flangev 14 for securingthe manifold to the engine block in the usual vided at the inlet forsecuring the carburetor unit to the manifold. Y y

The carburetor unit comprises a main housing 18, having an attachingflange 2() adapted to be secured to the flange 16 by screws 22, and anair inlet coupling 24 is secured inan manner, while aflange 16 is pro-yopening in the upper wall of the housing to admit air thereto. A casting26 in which the passages for supplying fuel to the nozzles are formed issecured to the lower wall of the housing 18 and a sheet metal fuel bowl28, is held tight against the bottom of the housing in any desirableway.` Fuel is conducted from a main source of supply to the fuel bowlthrough a conduit (not shown) and the "flow Yof fuel yto the bowl iscontrolled bya oat 30 g in the usual manner.H

Fuel fiows from the fuel bowl to a plurality of fuel nozzles 32 in eachof the primary mixing chambers 34, the construction of which is morefully describedA later.Av VFuel is conveyed to the lnozzles by avertical fuelv Vpassagef36 to which fuel is admitted at all enginespeeds'vby a fixed orifice 38and at high spe-eds by an orifice 40controlled by a .valve 42, which is operated in the manner described inthe above mentioned application.

The passage 36 connects with a horizontal fuel canal 44, supplying fuelto all of the primary ,fuel nozzles, while at they junction ofthepassages 36 and 44, there is formed an enlarged chamber 46 in which isreceived a check valve 48`adapted to seat on the bottom of the chamberand prevent downward flow of fuel through the passage 36 whenever thesuction in the mixing chambers falls', as for instance following aclosing movement of the throttle. Each fuel nozzle is provided withamain fuel outlet 50 in the top of the nozzle and a secondary fueloutletcomprising two orifices 52 and 54 in the vertical wall of the nozzlenear the bottom of the mixing chamber. At

intermediate and high speeds, they suction in the mixing chamberseffect-s a flowof fuel from the main fuel outlet as well as from thesecondary fuel outlets, but at idling or low speed operation under load,the suction is enough to lift fuel vonlyto a point between y is providedwith a restricted fuel metering the main and secondaryv fuel outlets,fuel flowing from the latter by thea'ction of gravity under suchconditions. Each nozzle orifice 56.

The primary mixing chambers constituteV i the large anterior ends of theprimary mixture passages 58 which are parallel and close together, asindicatedin Fig. 2. When the,

. carburetorit attached to the manifold, these passages register withconduits which convey the primary mixture tothe secondary mixi ngchambers, as disclosedV in the above mentioned application, the tube 60,fixed in the branch 12 of the, manifold, constituting the conduit forsupplying primary mixture to the secondary mixing chamber iii thatparticular manifold branch. A restriction 62 is provided in each of theprimary'inixture passages immediately in advanceof the fuel nozzles soas to reduce the velocity-of How past said nozzles for a purposefully'set forth in the gagement with Vthe valve, by means fully'journalled inthe housing.

spring 72, received between the valve and ange 74, projecting from asleeve 76, slidably mounted on a sleeve 78, fixed in the housing andguiding the stem 80, .to which the air valve is secured. The carburetoris adapted to be choked to facilitate starting of the engine by liftingthe sleeve 76 into endescribed in the above application. Sufficient airto carry the starting fuel to the inta ie ports is admitted through aslot 82 formed in a plate 84 secured to the main housing.V The valve 68admits air to a main air chamber 86 from which air iiows to thevpriiiiarj,r mixing chambers through an opening 88v in the bottom of theair chamber and to the secondary mixing chamber through a passage 90,which connects with the inlet of the manifold l0. Thel iiow of airthrough this passage iscontrolled by a manually operable valve92 and asuction operated valve 94 securedV to shafts 96 and 98 respectively,

.f .100 The operating connections for the throttle and the valve 92forinno part of the present invention and, therefore, are not describedhereiin; it being suiiicient for the purposes of this Ydisclosure to saythat the primary ,105 `throttle opera-tes the valve 92 through the'v*medium of an adjustable lost motion connection which permits `apredetermined movenient of the throttle independent vof the valve 92 andis generally adjusted so as to permit 110 the primary throttle to bemoved to a position corresponding to a vehicular speed of approximately20-25 miles per hour on the level without any accompanying movement ofthe valve 92. On further opening of the pri-v mary throttle, the valve92is moved siniultaiieous'ly therewith. f

On any increase of suction in the main air chamber, the valve 68 isopened to admit additional air and the opening of this valvelgo must beretarded to prevent fluttering of the valve-fand to restrict theadmission of air suiiiciently to enrich the mixture to some extent4during the acceleration period. For this purpose a dashpot is providedcompris-125 ing a cylinder 100, which receives fuel from the mainfuelreservoir, Aand a piston 102 slidable therein and secured to thestem of the air valve. The specific construction of the u dashpot is notmaterial to thepresent invendisclosed herein but is fullj.7 describedinthe abo-ve application, is provided to retard the opening of thisvalve to aid in enriching the mixture during the acceleration period, asis fully set forth 11i said application. In addition to the retardationof the opening of the valve `94, it has been found desirable to providea fuel pump which is operative to sup-l ply additional fuel to theprimary mixturej passages during the acceleration period. The abovedescribed dashpot which controls the opening of the main air pump and afuel delivery conduit 104 coniiects with the dashpot cylinder as shownin Fig. 1 and conveys fuel channel 106, formed in a block 108,*attachedto the lower wall of the main housing` and communicating with verticalpassages 110,v

there being three of these passages, one of which supplies fuel to eachof the primary mixture passages 58. This mechanism forms no part of thisinvention and is fully described in the above mentioned application.

As has been stated above, it is desirable to provide means foraccelerating the flow through the primary mixture passages s0 that theenriched mixture following an opening of the throttle will be deliveredto the secondary mixing chambers almost iinmediately after the throttleopens in order to secure smooth and rapid engine acceleration and toalso produce a high velocity of flow through the secondary mixingchambers in order to prevent precipitation of fuel from the mixture andpuddling of fuel on the w alls of said secondary mixing chamber.Heretofore, Venturi tubes have been positioned in the outlet branchesofthe manifold, such Venturi tubes forming the secondary mixing chambersand effecting a relatively rapid rate of flow therethrough. TheseVenturi tubes, in earlier forms of this device, been fixed in positionwith the throat of the Venturi tube adjacent the outlet of the primarymixture conduits. These devices are open to the objection that if theVenturi tube is made sufficiently small at the throat to produce thedesired acceleration of flow when the throttle is only slightly openedand a small quantity of air passing through the tube, such tube willrestrict the flow when the throttle is relatively wide Aopen to such adegree that a relatively highpartial vacuum is created within the tubesand a' consequent reduction in engine power results.

According to the present invention, Venturi tubes are employed-in theoutlet branches of the primary manifold and such tubes are normallypositioned, when the throttle 'is closed or nearly closed, so that thethroat is valve is utilized as a 1 to a horizontal fuel have I theventuri.

closelyadjacent thefoutlet of the primary mixture conduit.v TheseVenturi tubes, however,5are automatically movable as the quantity of airpassing` through the said Venturi tubes increases with the opening ofthe throttle, so' that the throats of the kVenturi tubes are moved awayfrom the end of the primary mixture conduit and the area of theavailable passage through which air must fiow is increased in accordancewith the increase in opening of the throttle.

For this purpose, each outlet branch of the manifold is provided with asleeve 120, which fits relatively tightly within the inanifold branchand at its end adjacent the en-r` gine, is bent over as shown in Fig. 1to form an inner sleeve 122, a space 124 being provided between the twosleeves. A 4Venturi tube 126 is slidably mounted within the sleeveV andis provided with a cylindrical extension 128 lwhich is received withinthe space 124 andfits relatively tightly in said space. The

sleeve 12() is adapted to be held in position by a set screw 121 or anyother suitable means,

and threaded or otherwise secured in sleeve '120 is a collar 130, whichlimits the movement Y of the Venturi tube in one Vdirection anddetermines the normal position when the engine is not running. Receivedwithin the space 124 between the end of the cylindrical extension 128and the closed end of the sleeve 120 is a spring 132, which normallymoves the Venturi tube into engagement with the 'collar 130. Holes 134are provided in the inner sleeve 122 to permit the escape of air from:the space 124. As above stated, the cylindrical extension 128 fitsrelatively tightly within the space 124 so that such extension and thespace constitute an air dashpot which retards the movement of theVenturiI v tube in either direction of its movement, the

tube being enabled to move only as rapidly 'as the air can pass out ofor into the space 12,4 through the orifices 134vand by leakage Varoundthe extension 128.

The operation of this device should be obvious on inspection. Normally,the Venturi tube is in the position shown in Fig. 1 with the throat-ofthe tube adjacent the end of the primary mixture conduit. If thethrottle is opened, a greater quantity of air flows through the venturiand this air in Yconjunction with the suction of the engine, moves theventuri to the right in Fig. 1, and the throat of the venturi away fromthe end ofthe primary mixture conduit, increasing the area of thepassage betweensaid conduit and The vmotion of the venturi is retardedby the action of the above described air dashpot so that the movement ofthe ven# turi is gradual and no damage to .the parts is effected due tothe rapid pulsations of the engine and consequent rapid changes insuction. As the throttle is moved toward closed position, the venturi isgradually moved in the `oppositedirection until it lreaches the positionshown in Fig. 1. This-device, therefore, acceleratesthe flow through thesecondary mixing chambers at all times when the engine is running, butsince the area of the passage therethrough is increased as the v.quantity of `air flowing through the chamber lis increased, the partialvacuum maintained therein is held substantially constant and the powerof the engine is not reduced.

In Fig. 3 is shown a somewhat modified form of the above described meansfor accelerating the air flow through the secondary 'mixing chamber andin this form the venturi is provided With a cylindrical eXtensionHO atits rear end which slides Within a spacelt similar to the space 124.-.This spa-ce is also provided with a springflll, Which in conjunctionwith the spring 132, causes the venturi to be in effect, a floatingventuri, its normal position being determined by the relative strengthof the two springs so that the venturi comes to rest When the springsreach a condition of balance. Y Y l While the form of embodiment of thepresent invention as herein disclosed, constitutes a preferred form, itis to be understood that other forms might be adopted, all coming Withinthe scope of the claims which follow.

lfVhat is claimed is as follows:

l. An intake manifold for a multicylinder internal combustion enginehaving a plural- ,ity of intake ports, comprising a plurality of Outletbranches adapted to communicate with said intake ports, movable meansadapted to reciprocate in said branches for controlling the velocity offlow therethrough and means for cushioning the .movement of movablemeans in both directions of its movement.

2. An intake manifold for a multicylinder internal combustion enginehaving a plurality of intake ports, comprising a plurality of outletbranches adapted to communicate With said intake ports, movable means insaid branches for controlling the velocity of flow therethrough, and adash-pot for ret-arding the movement of said movable means.

3. An intake manifold for a multicylinder internal combustion enginehaving a plurality of .intake ports, comprising a plurality of outletbranches communicting With such ports, conduits adapted to supply fuelto said manifold branches, a movable member in each of said branchesadapted to regulate thevelocity of flovv past the ends of said conduits,means normally holding said member in position to Vrestrict the passagethrough said outlet branch at a point adjacentl the outlet of said fuelsupply conduits and means for retarding the movement of said movablemember.

4. An intake manifold for a multicylinder internal combustion enginehaving a plurality of intake ports, comprising a plurality of V'outletbranches communicating With such the end of said ports, conduits adaptedto supply fuel to said manifold branches, a movable member adapted to bemoved toward and away from the outlet end of each of said fuel deliveryconduits to regulate the velocity of flow past conduit, and means forretarding the movement of said movable mem.- ber in both its directionsofmovement.

5. An intake manifold for a multicylinder internal combustion enginehaving a .plurality of intake ports, comprising a plurality of outletbranches communicating with such ports, fuel delivery conduitsprojecting int-o the outlet branches of said manifold, a movable memberin each of said branches havingv a restriction therein, and meansnormally holding each of said member in such position that therestriction therein is adjacent the outlet end of its associated fueldelivery conduit.

6. An intake manifold for a multicylinder internal combustion enginehaving a plurality of intake ports, Vcomprising a plurality 0f outletbranches communicating with such ports, fuel delivery conduitsprojecting into the outlet branches of said manifold, a movable memberin each of said branches having a restriction jthereimvrneans normallyholding each of said members in such position that` the restrictiontherein is adjacent the outlet end of its associated fuel deliveryconduit, and means for retarding the movement of said movable members.

l An intake manifold for a multicylinder internal combustion enginehaving a plurality of intake ports, comprising a plurality of outletbranches communicating with such ports, fuel delivery conduitsprojecting into the outlet branches of said manifold, a mov-A ablemember is each of said branches having a restriction therein, saidmembers being normally positioned so that the restriction therein isadjacent the outlet end of the fuel delivery conduit, and adapted to bemoved byl engine suction to vary the area of the passage at the end ofsaid fuel delivery conduit.

8. An intake manifold for a multicylinder vinternal `combustion enginehaving a plurality of intake ports, comprising a plurality of outletbranches communicating with such' ports, fuel delivery conduitsprojecting into the outlet branches of said manifold, and movableVenturi tubes Within said branches surrounding said conduits, saidVenturi tubes normally being positioned so that the throats thereof areadjacent the associated fuel delivery conduits.

9. An intake manifold for a multicylinder internal engine having aplurality of intakel ports, comprising a plurality of outlet branchescommunicating with such ports, fuel delivery conduits projecting intothe outlet branches of said manifold, suction operated Venturi tubes insaid manifold sur rounding said conduits and adapted to be loo moved asthe engine speed varies to vary the size of the passage'betWeen eachfuel delivery conduit and its associated Venturi tube.

10. An intake manifold for a multicylinder internal combustion enginehaving a plurality of intake ports, comprising a plurality of outletbranches communicating With such ports, fuel delivery conduitsprojecting into the outlet branches of said manifold, suction operatedVenturi tubes in said manifold surrounding said conduits, and means forretarding the movement of said Venturi tubes. y

11. In combination with the intake pipe of an internal combustion enginehaving yan intake port, a conduit for supplying a primary mixture offuel and air to `said intake pipe and means in said pipe for increasingthe velocity at Which the mixture is delivered from said intake pipe tothe intake port, said means comprising a movable passage restrictingmember and means for retarding the movement thereof. f

12. In combination with the intake pipe of an internal combustion enginehaving an intake port, a conduit'for supplying a primary mixture of fueland air to said intake pipe and means in said pipe for increasing thevelocity at which the mixture is delivered from said intake pipe to theintake port, said means comprising a movable Venturi tube, adapted tovariably restrict the pipe as it moves to different positions.

13. In combination with the intakepipe of an internal combustion enginehaving` an intake port, a conduit for supplying a prin mary mixture offuel and air to said intake pipe and means in said pipe for increasingthe velocity at which the mixture is delivered' from said intake pipe tothe intake port, said means comprising a suction operated Venturi tubeadapted to be moved to different positions as the engine speed varies.

14. In combination with the intake pipe of an internal combustion enginehaving an intake port, a conduit for supplying a primary mixture of fueland air to said intake pipe and means in said pipe for increasing thevelocity at Which the mixture is delivered from said intake pipe saidmeans comprising a movable Venturi tube adapted to variably restrict thepipe and means for retarding the movement of said Venturi tube.

15. In combination With the intake pipe of an internal combustion enginehaving an intake port, a conduit for supplying a primary mixture of fueland air to .said intake pipe and means in said pipe for increasing thevelocity at Which the mixture is delivered from said intake pipe to theintake port, said means comprising a movable Venturi tube adapted tovariably restrict the pipe,

other end of the sleeve to the intake port,

means for retarding the movement of said Venturi tube and means forreturning the said tube to its normal position.

16. In combination with the intake pipe of an internal combustion engine'having an intake port, a conduit for supplying a primary mixture offuel and air to said intake pipe and means in said pipe for increasingthe velocity at which the mixture is deliv.-

ered from said intake pipe to the intakev port, said means comprising amovable Venturi tube adapted to variably restrict the pipe, an outersleeve in which said tube is slidable, an inner sleeve parallel to saidouter sleeve throughout part of its length and spaced therefrom, aprojecting' portion of the Venturi tube extending into the space thusformed, means closing the other end of said space and means permittingonly a limited passage of air to and from space whereby it acts as adashpot to retard the movements of the Venturi tube.

17. In combination with the intake pipe of an internal combustionengine, of a removable unit adapted to be inserted in said pipe adjacentits outlet end to control the velocity of flow through said pipe intothe intake ports, said unit comprising a sleeve fitting Within theintake pipe, a Venturi tube slidable Within the sleeve, means positionedat one end of the sleeve to retard the movement of said Venturi tube, astop at the for determining the normal position of the venturi and meansfor retaining the sleeve in position in said intake pipe. Y

In testimony whereof I hereto aflix my signature.

CRAIG V. MORTON.

